1. Field of the Invention
The present invention relates to an insert rapier used for a both-side rapier loom.
2. Description of the Related Art
Weft insertion for a both-side rapier loom is typically performed by an insert rapier provided at a weft-feeding side and a carrier rapier provided at a side opposite to the weft-feeding side. The insert rapier holds the distal end of a weft connecting with a weft feeder, and carries the weft in a shed of warps to the center of the weaving-width. At this position, the weft is transferred to a carrier rapier inserted into the shed in the direction opposite to the weft-feeding direction. The carrier rapier carries the weft to the side opposite to the weft-feeding side.
The insert rapier may have a configuration in which a weft is spontaneously transferred by relative movement of the insert rapier and the carrier rapier (for example, see Japanese Unexamined Patent Application Publication No. 02-269835). To stably perform the weft insertion, the insert rapier needs to have a function of holding a weft, and a function of dividing warps so as not to incorrectly hold a warp (in particular, a defectively shed warp) during traveling in the shed of warps.
FIG. 16 illustrates an example of an insert rapier of related art used for a both-side rapier loom. In this specification, the side of the insert rapier which is advanced into the shed of warps first is the distal side (the weft-insertion side) and the side thereof which is retracted from the shed of warps first is the proximal side (the side opposite to the weft-insertion side). An insert rapier 81 includes a weft-holding portion 83 arranged at a bottom portion 85 of a rapier head 82. The weft-holding portion 83 holds a weft 20. The weft-holding portion 83 includes a catch base 83a and a catch piece 83b which are vertically arranged and respectively have facing surfaces 83f and 83e facing one another. A gap is defined between the facing surfaces 83f and 83e of the catch base 83a and the catch piece 83b. The gap is narrowed from the distal side toward the proximal side of the insert rapier 81. Thus, the gap defines a wedge-shaped gap 83c between the facing surfaces 83f and 83e. The gap 83c can hold the weft 20. One of the catch base 83a and the catch piece 83b is elastically pressed to the other, so as to pinch and hold the weft 20 by the gap 83c when the weft 20 is guided to the position between the catch base 83a and the catch piece 83b. When the weft 20 is transferred to a carrier rapier, the weft 20 is allowed to be pulled out of the gap 83c of the weft-holding portion 83.
A warp-dividing portion for dividing warps is provided at the distal side (the weft-insertion side) of the rapier head 82 with respect to the weft-holding portion 83. More specifically, a front wall 86 and a rear wall 87 of the rapier head 82, and a tongue piece 88 provided at the distal side of a head cover 80 define an upper warp-dividing portion. A lower surface of the bottom portion 85 of the rapier head 82 defines a lower warp-dividing portion. The front wall 86 and the rear wall 87 are provided in a region at the distal side of the rapier head 82 with respect to the weft-holding portion 83. The front wall 86 and the rear wall 87 protrude upward from both sides in the width direction of the bottom portion 85 of the rapier head 82, and have hill-like shapes extending in the longitudinal direction of the insert rapier 81. The front wall 86 and the rear wall 87 respectively have ridge portions including an upper ridge 86b having a top 86a, and an upper ridge 87b having a top 87a. A distal half portion of the front wall 86 overlaps with the rear wall 87 in a side view of the rapier head 82 (in the warp direction). Also, an upper guide portion 84a and a lower guide portion 84b are provided at the distal side of the rapier head 82 with respect to the bottom portion 85. The upper guide portion 84a and the lower guide portion 84b are tapered in the up-down direction (the thickness direction) and the front-rear direction, and converge at a distal tip 84. The upper guide portion 84a and the lower guide portion 84b connect with the upper and lower surfaces of the bottom portion 85.
The rapier head 82 includes the head cover 80 that tenses the weft 20 to allow the weft 20 to be transferred to the carrier rapier. The tongue piece 88 that is integrated with the head cover 80 has a distal portion 88d extending in the weft-insertion direction, i.e., in a direction in which the weft 20 is inserted. The distal portion 88d of the tongue piece 88 is located lower than the top 87a of the rear wall 87 in the side view of the rapier head 82, and located in a region between the front wall 86 and the rear wall 87 in a top view of the rapier head 82. The tongue piece 88 gradually descends toward the distal portion 88d located at the distal side while the extending direction is gradually shifted in the front direction toward the distal side with respect to the weft-holding portion 83.
FIGS. 17 to 19 illustrate the state in which the rapier head 82 introduces the weft 20 when the weft-holding portion 83 holds the weft 20. By traveling of the insert rapier 81, the weft 20 that extends to intersect with the warp direction at a predetermined angle to a warp direction (FIG. 17) contacts the upper ridge 87b of the rear wall 87, then contacts the upper ridge 86b of the front wall 86 while being in contact with the upper ridge 87b of the rear wall 87, and then is separated from the upper ridge 87b of the rear wall 87 while being in contact with the upper ridge 86b of the front wall 86. The weft 20 is moved toward the proximal side relative to the insert rapier 81. In the course of the movement, the weft 20 reaches the distal portion 88d of the tongue piece 88 (FIG. 18). The shapes of the front wall 86, the rear wall 87, and the tongue piece 88 are determined such that the distal portion 88d of the tongue piece 88 is located higher than the weft 20 that obliquely extends in the region between the front wall 86 and the rear wall 87 in a top view. Thus, the weft 20 enters a gap 89 between the rear wall 87 and the tongue piece 88. When the insert rapier 81 moves, the weft 20 is relatively moved in the direction opposite to the weft-insertion direction (toward the proximal side) within the gap 89, and is guided to the weft-holding portion 83. The weft 20 is tucked into the space between the two members (the catch base 83a and the catch piece 83b) of the weft-holding portion 83 and held by the two members (FIG. 19).
FIGS. 20 to 22 each illustrate the state in which the insert rapier 81 divides defectively shed warps 21 during weft insertion. The warps 21 that form a shed are orthogonal to the weft-insertion direction (the advance direction of the insert rapier 51) (FIG. 20). If incompletely shed warps 21 are produced due to entangled fluff, when the insert rapier 81 moves, the defectively shed warps 21 on the travel path of the insert rapier 81 are moved toward the proximal side relative to the insert rapier 81 while being in contact with one of the upper ridges 86b and 87b of the front and rear walls 86 and 87. The warps 21 reach the distal portion 88d of the tongue piece 88 (FIG. 21). The shapes of the front wall 86, the rear wall 87, and the tongue piece 88 are determined such that the distal portion 88d of the tongue piece 88 is located lower than the warps 21 that extend between the front wall 86 and the rear wall 87. Accordingly, the defectively shed warp 21 contacts an upper ridge 88b of the tongue piece 88. When the insert rapier 81 moves, the warp 21 is tossed upward by the upper ridge 88b of the tongue piece 88 and an upper ridge of the head cover 80. Thus, the warps 21 pass above the insert rapier 81 without entering the waft holding portion 83 (FIG. 22).
The insert rapier 81 causes the weft 20 to be held by tucking the weft 20 into the region between the two members (the catch base 83a and the catch piece 83b) which are elastically pressed to one another. When the weft 20 is transferred to the carrier rapier, the insert rapier 81 causes the weft 20 to be released by relatively retracting the carrier rapier, to which the weft 20 has been transferred, so that the weft 20 is spontaneously pulled out of the two members (the catch base 83a and the catch piece 83b). Also, the function of dividing the warps 21 and introducing only the weft 20 to the weft-holding portion 83 is realized on the basis of the angle of the weft and the positional relationship among the front wall 86, the rear wall 87, and the tongue piece 88 provided at the rapier head 82. As described above, the weft 20 can be held and transferred (released) with the simple configuration, while the warps, in particular, the incompletely shed warps 21 can be prevented from being incorrectly held by the weft-holding portion 83.
As described above, the insert rapier 81 causes the weft 20 to be held by tucking the weft 20 into the region between the two members (the catch base 83a and the catch piece 83b) which are elastically pressed to one another. For example, in a case in which an entirely disconnected (easily separated) weft 20, such as a multifilament yarn made of a large number of monofilaments, is held, the entire weft 20 is pressed by the facing surfaces 83e and 83f of the two members. The filaments of the weft 20 may be tucked into the wedge-shaped gap 83c while being separated in a plane. Also, the holding force for the filaments becomes small at the position at which the gap is large. Bending stress may be intensively exerted on filaments which are relatively completely held from among the filaments. Consequently, the filaments may be broken, or the weft 20 may be split while the insert rapier 81 travels after the insert rapier 81 holds the weft 20.
Also, in the insert rapier 81, the gap 89 between the rear wall 87 and the tongue piece 88 is as narrow as possible to prevent the warps 21 from incorrectly entering the weft-holding portion 83. Owing to this, the entirely disconnected weft 20 or a weft having a special shape (a tape-like weft with a large width, such as a flat yarn) may be entirely hooked to the tongue piece 88 and may not enter the narrow gap 89. The weft 20 may not be guided to the weft-holding portion 83, and hence, the weft-holding portion 83 may not catch the weft 20. The productivity of woven fabric may be degraded.
Meanwhile, an insert rapier of related art may include a weft-holding portion that is actively opened and closed (Japanese Examined Patent Application Publication No. 46-20112). The insert rapier includes a base surface provided at the distal side of a holding head (corresponding to a rapier head in this specification), and a holding lever (corresponding to a catch lever in this specification) that has a facing surface facing the base surface and is urged to press the base surface. The holding lever is actively opened and closed to allow a weft to be held between the base surface and the facing surface before weft insertion. However, since the weft-holding portion (the holding lever) is provided at the distal side of the insert rapier, a size residue and dust tend to remain at the weft-holding portion. The engagement between the holding head and the holding lever may be insufficient. If the rapier head enters the shed of warps while the weft-holding portion provided at the distal end of the rapier head is even slightly opened, an incompletely shed warp due to entangled fluff may be hooked to the rapier head, and the warp may be cut.